Recently, the use of electronic devices, such as mobile communications apparatuses, including smart phones equipped with electrostatic capacitive touch panels have spread widely. Besides mobile telecommunications apparatuses, the number of electronic devices provided with capacitive touch panels, capacitive sensors and the like devices for input controllers increases so that the devices can be manipulated by executing predetermined input operations.
Such an electronic device is provided with, for instance, a transparent capacitive sensor disposed on a front screen of a display unit, such as a liquid-crystal display. A user visually identifies certain icons or menus that appear on the display unit through the sensor, and selects a desired icon or item. In other words, the user makes various input operations by touching certain positions of the sensor corresponding to the desired icons and menus with a finger.
When the user executes the touching operation by touching a position on the capacitive sensor with a finger, a capacitance at the position of the capacitive sensor changes. A controller installed in the device detects the touched position based on the change in the capacitance, and actuates a functional component assigned to the selected icon or menu.
Many of such electronic devices can detect manipulated positions when touched with either a bare finger or a gloved finger wearing a glove. The change of the capacitance of the capacitive sensor becomes smaller when the manipulation is made by touching it with the gloved finger than to touching with the bare finger. Therefore, in order to determine both of these touching manipulations, a reference value is predetermined for values of the changes of the capacitance resulting from the touching manipulations, as disclosed in, e.g. PTL 1. When a value of the change of the capacitance obtained by a touching manipulation is larger than the reference value mentioned above, it can be determined that the touching manipulation is made with the bare finger, or, when the value of the change of the capacitance is smaller than the reference value, it is determined that the touching manipulation is made with the gloved finger.
The conventional electronic device using a predetermined reference value for determining which of bare finger or a gloved finger the touching manipulation is made with can determine it with certain accuracy. However, the determinations may not be made accurately depending on such circumstances as places and conditions of use.